The present invention relates to a condenser particularly adapted for use in automobile air conditioning systems.
For such use, a "serpentine" type of condenser is well known and widely used. This condenser is made up of a multi-bored flat tube, commonly called "harmonica" tube, bent in zigzag form, and corrugated fins sandwiched between the bent tube walls. In this way a core is constituted.
The cooling medium path in a condenser is roughly classified into two sections, that is, an inlet side section and an outlet side section. In the inlet side section the cooling medium is still in a gaseous state, and in the outlet side section it becomes liquid. In order to increase the efficiency of heat exchange the area for heat exchange of the inlet side paths should be as large as possible. On the other hand, that of the outlet side paths can be relatively small.
Since the "serpentine" type condenser consists of a single cooling medium path provided by a single pipe, an increase in the area for heat exchange in the inlet side section increases that of the outlet side section. As a whole the size of the condenser becomes large.
The inventors have made an invention relating to a "multi-flow" type condenser instead of the serpentine type, which is disclosed in Japanese Patent Publication (unexamined) No. 63-34466. The multi-flow type condenser includes a plurality of tubes arranged in parallel, corrugated fins sandwiched therebetween, and headers connected to opposite ends of the tubes. The headers have partitions which divide their inner spaces into at least two sections including an inlet side group of paths and an outlet side group of paths, thereby causing the cooling medium to flow in at least one zigzag pattern. The total cross-sectional area of the inlet side group of paths progressively diminishes toward the outlet side group. In this way the inlet side section has an optimum area for accommodating the cooling medium in a gaseous state, and the outlet side section has an optimum area for accommodating the medium in a liquid state. Thus the multi-flow type condenser has succeeded in reducing the size of condensers without trading off the efficiency of heat exchange. However, one problem which arises is determining the portion of the whole path which is divided into the gaseous phase side (i.e. the inlet side section) and the liquid phase side (i.e. the outlet side section) by partitions. Improper proportioning unfavorably affects the efficiency of heat exchange and causes pressure loss on the flow of the cooling medium.
If the area in the outlet side section is insufficiently reduced as compared with that of the inlet side section, it becomes difficult to secure a sufficiently increased cross-sectional area of the inlet side section. As a result, the cooling medium undergoes a larger pressure loss, and the efficiency of heat exchange decreases because of the relatively small area for heat exchange. If, however, the area in the outlet side section is excessively reduced as compared with that of the inlet side section, pressure loss is likely to increase on the flow of the cooling medium. The area for heat exchange of the inlet side section becomes too large, thereby slowing down the flow rate of the cooling medium.
Accordingly, it is an object of the present invention to provide a condenser having cooling medium paths divided in an inlet side section and an outlet side section in an optimum proportion, thereby increasing the efficiency of heat exchange and reducing the pressure loss of a cooling medium.
Other objects and advantages of the present invention will become more apparent from the following detailed description, when taken in conjunction with the accompanying drawings which show, for the purpose of illustration only, one embodiment in accordance with the present invention.